An image display apparatus including a first waveguide, a second waveguide, a focus tunable lens positioned between the first waveguide and the second waveguide, and a display engine configured to control a focal length of the focus tunable lens and control the display engine to output first light forming the first virtual image and second light forming the second virtual image, wherein at least a portion of the first light is diffracted from the first waveguide and at least a portion of the second light diffracted from the second waveguide is incident on the first waveguide through the focus tunable lens.